Round corner



74.1fm 9 1S Patented Nov. 1, 1938 UNITEDSTATES ROUND CORNER Richard H. Crouch, Pulaski, Va.,

assignorto Automatic Machinery Corporation, Pulaski, Va., a corporation of Virginia Application April 13, 1936, Serial No. 74,200

3 Claims.

to an improvement in solid, durable and uniform throughout its outerand rounded surface without bulging at the ends of the corner post or core.

The patent to Berg, No. 1,981,494, dated November 20, 1934, discloses different forms for accomplishing this end, and in a modification of the preferred form he shows the corner post,

with a; specially formed groove at each edge adapted to interlock and interfit with counter part grooves in the inner edges of the side members which go to form the corner construction, but in this type of structure there are two objections which are overcome by my present invention:

(1) One objection is that it presents a weakness at the outer edges of the corner post, which sooner or later results in bulging at those two points due to the pressure applied in forming the corner structure; and r (2) The second defect is that it is impossible in this form of structure to pull or bend the relatively thin veneer or plywood section around the outer curved surface of the corner post because it is in the nature of a lock joint.

In my corner the workman can lay the core or corner post in the cut and clamp all parts together in one operation. Thus in my invention I have overcome both the foregoing objections by preventing bulging at the joints, and by my method of construction I can pull or bend the relatively thin section of veneer or plywood around the corner piece, or, if preferred, I can slide the latter lengthwise into the space formed therefor as is necessary in the Berg construction.

One object of my invention is to provide a device of this type and a method whereby to produce a smooth, symmetrical, rounded surface at the corner joint formation for use in the manufacture of different articles of furniture, wagonboxes, and the like.

. With the foregoing objects in view, this'invention consists in a corner made by inserting a filler core block having an outer surface shaped to the corner form desired, and the edges fashioned to fit corresponding edges of a recess extending transversely through a strip of the material of which the corner is formed, at the back i of which recess is left a thin, flexible portion adapted to be drawn'around the curved surface of the filler or block, whereby the counterpart edges of the latter and the recess are-brought together and securely held to complete the curved corner structure. I a g In the accompanying drawing: 1 l Fig. 1 is a view in perspective showing a transversely recessed strip with athin portion left-at the back and a filler coregblock in position to ,be

inserted in the recess;-

Fig. 2 is an illustration showing how'the recesses of this type may be formed; 7 r

Fig. 3 is a view in perspectiveof the'completed corner;

Fig. 4 is aplan view of the same; and Fig. 5 is a viewillustrating the preferred method of laying the core or corner-post in the cut and clamping all parts together in one operation. The numeral I represents a .core of material such as wood, preferably faced on both sides with veneer or plywood 2 and 3, and 4 is a recess which might be variously formed, as for instance by a cutter-head 5. This recess 4 is of a depth to leave theplywood or veneer 3 intact, and the edges 1 of the recess are irregularly grooved as surface 9 shaped to the form of corner desired, preferably in the arc of a circle as illustrated, and this block 8 is provided with irregular shaped edges I 0, which conform to and are a counterpart of the edges 7 of the recess 4.

The recess 4 is initially of greater width than the block 8 as illustrated in Fig. 1, but when the ends of the strip 2 are brought around to the positions shown in Figs. 3 and 4, the part 6 is drawn tightly around the curved surface 9 of the block 8, and the edges IU of the straight and inner surface ll of the securely embraced and held in the position shown in Figs. 3 and 4. The foregoing is made possible by reason of the specially planned edge groove formation of the filler core block 8, which will permit of the ends I being swung around in arcs of circles sprung from a point at or near the center of the block 8, and from an initial position such as illustrated in Fig. 1 to that shown in Figs. 3 and 4. This is made possible by reason of the precise transverse shape or contour of the filler core block from the ends of curved surface 9 transversely all the way round the grooved edges and the flat or straight inner surface ll.

One of the desirable features of my present invention is to create a substantially uniform pressure between the points marked a and b and c, and this is accomplished by pulling the flex ible part 6 around the curved surface 9 of the filler core block 8 with the result that it allows the quarter circle at the corner to assume a smooth and regular form without causing a bulge at the points marked d, which has been the diificulty and a real problem in previous types of corner joints.

While I have described and illustrated a plan of cutting the recess 4 transversely through a strip as illustrated in Fig. 2, it is perfectly obvious that the ends I might be made separately with the edge grooves I and glued to the plywood or veneer 3 at the proper distance apart, thereby making provision for the recess 4. Either plan would come within the scope of my invention.

It is obvious that glue may be applied to all of the contacting surfaces of the joint before the parts are pulled around the filler core block.

In Fig. 5, I have attempted to illustrate my preferred method of infolding and clamping the core or corner post, and it consists in inserting a block 8 in the recess in any convenient way either endwise'or edgewise, and then bringing the ends I around as illustrated in dotted lines, whereupon the long beveled edge l5 of the ends I will engage the beveled edges 16 of the filler core block 8', the two surfaces l5 and I6 having a sliding cam action upon each other, with the result that the block 8 is centered and approximately uniform pressure is applied thereon at every contacting point by the time the ends I are brought into place as illustrated in Fig. 4, thus giving. a continuous and uniform curvature to the corner, and maintaining the shape thus imparted by the formation as a result of the complete interlock and uniform distribution of pressure throughout.

I claim: v

1. A construction of the class described comprising, two sides located adjacent a corner and having undercut grooves near their adjacent edges, a corner post interposed between the adjacent edges of the sides and abutting thereagainst and. having integral tongues extending into said undercut grooves and an outer lamination attached to the outer surfaces of said sides and extending continuously around the outer surfaces of said corner post.

2. A construction of the class described comprising, two sides located adjacent a corner and having undercut grooves in their inner surfaces, a corner post interposed between the adjacent edges of the sides and abutting thereagainst and having integral tongues extending into said undercut grooves and an outer lamination attached to the outer surfaces of said sides and extending continuously around the outer surfaces of said corner post.

3. In a construction of the character described comprising two sides connected by a relatively thin flexible strip, the edges of the sides adjacent to the flexible strip undercut at approximately right-angles next to the flexible strip, then in the direction of the sides and appro-Ximatelyparalleltherewith, then at approximately rightangles to the flexible strip and finally toward each other at an obtuse angle in combination with a core having a rounded surface around which the flexible strip is bent and having its remaining portion cut to fit the under cut angles of the sides.

RICHARD H. CROUCH. 

